我段运用的东方红<3>、<5>型机车装配的NT_2—00—75型总风缸高压保安阀(其它型号的国产机车一般也装用此阀,图1)系机车总风系统的安全装置。该阀一直存在开启压力正常,关闭压力偏低的问题。经测试多台机车得知,高压保安阀一般都能在9.5公斤力/厘米~2时开启,而装车不合格的保安阀的压力大多为6.5—6.8公斤力/厘米~2(接近列车管压力6公斤力/厘米~2),甚至有个别的低于列车管压力。当控制空气压缩机的风压继电器失灵时,压缩空气压力就会超过高压保安阀的开启压 I used the Dongfanghong <3>, <5> type locomotive assembly NT_2-00-75 total cylinder high pressure safety valve (other models of domestic locomotives are generally equipped with this valve, Figure 1) Department of locomotive wind system safety devices. The valve has always been open pressure is normal, the problem of low closing pressure. After testing several locomotives learned, high-pressure safety valve can generally be opened at 9.5 kg / cm ~ 2, and failed to load the security valve pressure mostly 6.5-6.8 kg / cm ~ 2 (close to the train tube Pressure 6 kg / cm ~ 2), there are even individual train pressure below the train. When the air compressor control air pressure relay fails, the compressed air pressure will exceed the pressure relief valve opening pressure